Process of desulfurizing and agglomerating comminuted ores.



No. 875,332. y PATBNTED 1330.31., 11.907.

A. J. DULME J. WEATHERBY, JR.

PROCESS OF DESULFURIZING AND AGGLOMERATING CMMINUTED GRES.

APPLIGATION FILED $213.4, leo?.

LLlLELLE N"ofr8`7532l PATENTED DBC; 31, 907.

' A. J. BULL & J. WEATHERBY, $3.,

PROCESS 0F DESULFRIZNG AND AGGLMBBANNG GMMINTED GRES.

. APPLIoATIoH FILED rm. 4. 1907.

2 sums-SHEET 2.

narran sarrrras ANDREW J. DULL, Ol llRltlSlUlG. AND JOSEPH lllNNSYl/VANIA; SAID WEA'FI'IERBY i"\' l`lll.ltllY, llt., Ol" NEW CUMBERLAND,

ASSIGNOR T() SAID DULL.

PROCESS OF DESLFURIZING AND AGGLOMERATING COMMINUTEORES.

Specification of Letters Patent.

Patented Dec. 31, 1907.

Application tiled February 4. 1907. Serial No. 355,692.

To all whom it may concern:

Be it known that we, AisnREw J. DULL, a citizen of the United States, residing; at Harrisburg', in the county of Dauphin, State of Pennsylvania, and JOSEPH VEATHERBY, Jr., a citizen of the United States, residing; at New (hnnberland, 'in the county of Cumberland and State of Pennsylvania, have invented certain new and useful Improvements in Processes of l.)esulfurizing and Ae;-

glomerating (lomminuted (ii-es; and wc do declare the following to be a full, clear, and exact description of the inxf'ention, such as will'enable others skilled in the art to which it aplnrtains to make and use the same..

(hninvention is an improved process of desulfurizing and agglomeratingv eomminuted ore to convert the same into a cinder, which may be subsequently treated in a blast furnace, and it consists in primarily heating comminuted ore to a degree. su'l'licient to burn out the major portion of the sulfur, but insu'llicient to fuse. the ore, and then subjecting such heated and partiall}r de-sulfurized ore to the action of an electric arc maintained 'for a sullicicnt period of time to partially fuse the ore and reduce it to the condition of an afgelomera ted mass or cinder of sullicient size and weight to enable it to be treated in a blast furnace without danger of being' blown out ol' such blast furnace by the action of the blast.

(hir invention further consists in subjecting' heated comminuted ore to the action of an electric arc, the oxygen olI which serres topromote the consumption and iiberation of they sulfurous content of the ore, and the heat of which agglomeratcs or cinders the ore.. Our invention further consists in reducing 40 the resistance of comminuted ore by primarily heating thesame. to facilitate the agglomeration thereof by the action of an electric are.

(lur invention further consists in subjecting heated comminuted ore to the action of an electric arc produced between two electrodes, one. of which is movable with reference to the other to cause the heated ore to be agglomerated by the action of the arc, and the cinder thus produced to be broken oll` and removed from the sphere of action of the arc by the movement of one of the electrodes with reference to the other.

Our invention further consists in converting a non-magnetic ore into a magnetic ore by subjecting the same to the action of an electric arc.

1n the accompanying' drawings,--Figure 1 is a diagrammatic sectional view of a roasting furnace of the stirrer type, provided With means for de-sulfurizing and aggleinerating coniminnted iron orc in Yaccordance with our improved process; Fig. 2 is a detaih sectional view illustrating the construction ofone of the electrodes; Fig. 3 is a-detail top plan View of the same; Fig. 4 is a similar view showing a inodiiied form of electrode; Fig. 5 is a diagrammatic sectional VieWofj'a to be used l'or "trrying out our-improved process.

ln order to adapt a roasting furnace of the stirrer type, such as shown in- Fig. 1, for use in carrying' out our improved processy we provide one vor more electrodes 1, which are placed on one or more of the lower roasting lioors c. 'fhese electrodes are connected by suitable conductors 2 to the negative pole of a generator, indicated at 3. The shaft b of the furnace is utilized as a conductor, and hence the teeth (l of the stirrer-arins c revolved by the said shaft, become electrodes, which move over the electrodes 1 at a suitable distance therefrom. The comminuted ore., with its sulfurous content, is fed linto the upper end of the furnace by means of the yhopper e, pan j' and chute q.

'l`hc interior of the furnace is heated by the usual means and in the usual manner, and combustion therein is maintained in the usual way, the heat being of such a degree as is sullicient to consume the major portion of the sulfur, but insuilcient to fuse the ore. Owing* to the stirring' action'of the stirringarms and lingers over the lloors of the furnace, and the descent of the ore 'from iloor to lloor of the furnace, the maj'or portion of the sulfur is removed from the ore before the ore reaches the floor or viloors on which the electrode or electrodes 1 is or are placed. As the electrodes formed by the fingers of the rakes over such, floor orlloors inove over such electrode or electrodes 1, electric arcs are formed between the electrodes of the movable rakes or arms and the iixed electrodes A1, and theV ore on the said floors while in its heated condition is subjected to the action of such arcs, the heat of which is vsuper-added to the heat caused by the combustion in the furnace, and the said arcs cement furnace modified to enable the saine serve to still further reduce the percentage of sulfur in the ore, and to partially fuse the ore so that the same becomes agglomerated or formed into cinders, which are usually porous, and which vary in size from about that of a pea to about that of an egg, Vand which are of sufficient weight to be adapted to be treated finally in a blast furnace without` danger of beine,` blown out of the blast furnace'by the force of the blast. Owing to the fact that each arc has an electrode which is movable 4with reference to the otherY and which moves past the other, the "cinder or agglomerated mass of ore formed between two such electrodes becomes broken therefrom by the movement of the movable electrede, so that such cinder or agglomerated mass, immediately after it has been formed, is taken out of the sphere of action of the arc, so that a given portion oll the. orc is only momentarily exposed to the action of an electric. arc. 'l'hc ore thus "cii'idered or agglomerated is discharged through the. draw-oil pipe. /t of the furnace b v the action of the arms or rakes over the lloors of the furnace. Products of combustion escape. from the furnace through the exit pipe 'i in the roofl thereof.

We have found bythe working of our imn proved process that the yelectrical resistance of ordinary coinminutml iron ore with a sulfurous content is greatly decreased by heating, so that such ore when highly heated, is

" agglomerate or cind'ery of very much lower resistance] than when cold, "the degree of heat in an ordinary roastii'ig furnace, such as here shown, while sullcient to eliminate the greater portion of the sulfur is insullicient to'fusc the orc. Our invention consists in superheating such heated ore electrically by exposing it to the action of an electric arc, and we find that an arc of sullicient intensity to de-sull'm'ixe, and the oreymay be maintained b v an electric current of comparativelylow voltage, hence n e greatly reduce .the power required'lor producing the lcurrent used in,carryingl out'our improved process and inso doing ell'ecta corresponding economy and to a (orrespomling extent obviate loss by leakage of the current. We lind ordimlry comminuted iron ore vtith. a sulfuricl content to be non-magnetic, but that` .when rsuch ore has been agglomerated or cilulered by our improved process, the same has been so converted as to be magnet-ic to'a comparatively high degree.

In practice, we have made t'heclcctrodes l of cast iron ol circular and segmental lorm,

have embedded the same in asbestos, as at 4,

and have further insulated the same by means of fire-brick 5, in which the asbestos has been embedded, so that. only thev upper surfacesl of the electrodes 1 are exposed.

ln Fig. 5 we show an ordinary revolving cement furnace, modified for use in carrying out our improved process. In Athis furnace an electrode 6 is provided, which is in the form of an iron ring placed in the furnace and of by tire-lnick rn.` At a suitable distance in advance of the annular electrode 6, and spaced therefron'i, we provide anumber of electrodes 7, nhich project through and are4 8. One pole of the Qenei'ator, indicated at 9, is connected to the annular electrode 6. '.lhe other pole thereof .is connected by a conn duetor 1() to a contact device 11, with which the electrodes 7 successively make sliding contact as the furnace revolves, so that an t arc is established between each electrode 7 as it reaches the lower side of the furnace, and

momentarily established and pretermitted is in effect identical with that hcreinbcfore dcscribed.

llavingr thus described our invention, what we claim as new, and desire to secure by lietters-'Paten is,-

l. 'lhe process of d'esulfurizing and agglomeratinp; ore,' consistintr in heating the same to a degree sullicient to burn out the 'major portion of the sulfur, but insullicient to fuse the ore, and subjecting' such heated and partiallydesull'urized ore to Vthe action of an electric are, substantially as described.

2. 'lhe process of auglomerating ore by exposintr the saine to the action of an electric lrespect to the other to break olll the agglomerated ore mass.

C5. 'l`hc process ol" agglomcrating ore by irst heatingr the saine to reduce its electrical resistance, e.\'posn, r the heatedl orc to thc action ol' an electric arc, and moving; one ol'v the electrodes, between which the arc isproduced, with respe. (`:t to the'other to break oll` the agglomerated ore mass vor einder between them, and removing such mass or cinder from the sphere. of action of the arc.

.ln testimony whereof wc have hereunto set our hands in presence o'f two subscribing witnesses,

ANDI-HCW J. HULL. J( )SlCPl'l W llA'll llC ltBY, JR. Witnesses ,l

Jos. lf". Wie/ivan, EDWARD M. lWliv'rnns.

insulated from the metallic cylinder c theref' insulated from the shell of the furnace, as at.

vthe electrode n. .'l`he action of the arcs thus arc, and moving' one of the. electrodes with 

